Those messages come from evince. They are emitted when evince detected a PDF file change and it reloads the file.
You can workaround this via redirecting `stderr` of evince to `/dev/null`. That means you can search for the evince call in the vim-latex plugin source and replace something like
evince
with:
evince
Alternatively, you can place a small wrapper script in your `PATH` \- when running vim with the vim-latex plugin. For example something like this:
$ mkdir -p ~/local/bin
$ cat ~/local/bin/evince
#!/bin/sh
exec /usr/bin/evince "$@" 2>/dev/null
$ chmod 755 ~/local/bin/evince
$ PATH=$HOME/local/bin:$PATH vim some_latex_file